yuzu/externals/vcpkg/packages/boost-context_x64-windows/include/boost/context/pooled_fixedsize_stack.hpp

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// Copyright Oliver Kowalke 2014.
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
#ifndef BOOST_CONTEXT_POOLED_pooled_fixedsize_H
#define BOOST_CONTEXT_POOLED_pooled_fixedsize_H
#include <atomic>
#include <cstddef>
#include <cstdlib>
#include <new>
#include <boost/assert.hpp>
#include <boost/config.hpp>
#include <boost/intrusive_ptr.hpp>
#include <boost/pool/pool.hpp>
#include <boost/context/detail/config.hpp>
#include <boost/context/stack_context.hpp>
#include <boost/context/stack_traits.hpp>
#if defined(BOOST_CONTEXT_USE_MAP_STACK)
extern "C" {
#include <sys/mman.h>
#include <stdlib.h>
}
#endif
#if defined(BOOST_USE_VALGRIND)
#include <valgrind/valgrind.h>
#endif
#ifdef BOOST_HAS_ABI_HEADERS
# include BOOST_ABI_PREFIX
#endif
namespace boost {
namespace context {
#if defined(BOOST_CONTEXT_USE_MAP_STACK)
namespace detail {
template< typename traitsT >
struct map_stack_allocator {
typedef std::size_t size_type;
typedef std::ptrdiff_t difference_type;
static char * malloc( const size_type bytes) {
void * block;
if ( ::posix_memalign( &block, traitsT::page_size(), bytes) != 0) {
return 0;
}
if ( mmap( block, bytes, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON | MAP_FIXED | MAP_STACK, -1, 0) == MAP_FAILED) {
std::free( block);
return 0;
}
return reinterpret_cast< char * >( block);
}
static void free( char * const block) {
std::free( block);
}
};
}
#endif
template< typename traitsT >
class basic_pooled_fixedsize_stack {
private:
class storage {
private:
std::atomic< std::size_t > use_count_;
std::size_t stack_size_;
#if defined(BOOST_CONTEXT_USE_MAP_STACK)
boost::pool< detail::map_stack_allocator< traitsT > > storage_;
#else
boost::pool< boost::default_user_allocator_malloc_free > storage_;
#endif
public:
storage( std::size_t stack_size, std::size_t next_size, std::size_t max_size) :
use_count_( 0),
stack_size_( stack_size),
storage_( stack_size, next_size, max_size) {
BOOST_ASSERT( traits_type::is_unbounded() || ( traits_type::maximum_size() >= stack_size_) );
}
stack_context allocate() {
void * vp = storage_.malloc();
if ( ! vp) {
throw std::bad_alloc();
}
stack_context sctx;
sctx.size = stack_size_;
sctx.sp = static_cast< char * >( vp) + sctx.size;
#if defined(BOOST_USE_VALGRIND)
sctx.valgrind_stack_id = VALGRIND_STACK_REGISTER( sctx.sp, vp);
#endif
return sctx;
}
void deallocate( stack_context & sctx) BOOST_NOEXCEPT_OR_NOTHROW {
BOOST_ASSERT( sctx.sp);
BOOST_ASSERT( traits_type::is_unbounded() || ( traits_type::maximum_size() >= sctx.size) );
#if defined(BOOST_USE_VALGRIND)
VALGRIND_STACK_DEREGISTER( sctx.valgrind_stack_id);
#endif
void * vp = static_cast< char * >( sctx.sp) - sctx.size;
storage_.free( vp);
}
friend void intrusive_ptr_add_ref( storage * s) noexcept {
++s->use_count_;
}
friend void intrusive_ptr_release( storage * s) noexcept {
if ( 0 == --s->use_count_) {
delete s;
}
}
};
intrusive_ptr< storage > storage_;
public:
typedef traitsT traits_type;
basic_pooled_fixedsize_stack( std::size_t stack_size = traits_type::default_size(),
std::size_t next_size = 32,
std::size_t max_size = 0) BOOST_NOEXCEPT_OR_NOTHROW :
storage_( new storage( stack_size, next_size, max_size) ) {
}
stack_context allocate() {
return storage_->allocate();
}
void deallocate( stack_context & sctx) BOOST_NOEXCEPT_OR_NOTHROW {
storage_->deallocate( sctx);
}
};
typedef basic_pooled_fixedsize_stack< stack_traits > pooled_fixedsize_stack;
}}
#ifdef BOOST_HAS_ABI_HEADERS
# include BOOST_ABI_SUFFIX
#endif
#endif // BOOST_CONTEXT_POOLED_pooled_fixedsize_H